Metal foil matrix



July '7, 1953 F. J. RUSSELL, JR

METAL FOIL MATRIX Filed Jan. 7, 1950 INVEN TOR. Fan/c J izkgse/'fi,

Patented July 7, 1953 METAL FOIL MATRIX 7 Frank J. Russell, Jr.,Marquette, Mich.

Application January 7, 1950, Serial No. 137,434 10 Claims. (01.154--46.5)

This invention relates to stereotype mats, and

more particularly to mats which'are adapted to be inserted in atypewriter to have type impressions formed therein.

The most widely used type of stereotype mat or matrix is made up of aplurality of layers of cellulose fibers felted together, along withother suitable ingredients which improve the finished product. Such matsmay be of the so-called wet mat type or the dry mat type, but in anyevent, the manner of utilizing each of these types is substantially thesame. As soon as a form containing the type has been set up, astereotype mat is placed thereon and then covered with blankets or feltsand passed through a rolling machine whereby the mat receives a reverseimpression of the type. The mat, after suitable drying, is placed in acasting machine where it is held in the form of a cylinder. Moltenstereotype metal is then poured into the casting machine whereby 'ametalcylinder or semi-cylinder is obtained which contains on its outersurface an exact duplicate of the type in the original flat form. Thisstereotype plate may then be placed in a rotary press and copies is ofthe printed material canbe produced at a high rate of speed. Severalcasts can normally be made from the same mat so that a number of pressescan be placed in operation almost simultaneously if desired. i

The form containing the type referred to above from which the matreceives its impression is normally made up of lines of type produced bya Linotype machine or similar device which automatically casts lines oftype from molten metal as it is being operated. Needless to say, devicessuch as Linotype machines are very expensive, and therefore any methodof preparing a matrix such as described without the necessity of usingsuch a machine would be very desirable. For example, if an ordinarytypewriter or an electric typewriter could be substituted for a Linotypemachine, a very substantial expense could be eliminated.

It is therefore an'object of this invention to provide a foil mat foruse as a matrix in forming stereotype plates, which mat is adapted to beinserted in a typewriter to have type impressions formed therein andwhich can subsequently be used to form printing plates, either in a fiator circular form, or may be used to form plates of type which can inturn be used to form the conventional type of matrix from which thestereotype plates normally are formed.

It is a further object of this invention 30 pro-- vide a matrix of thecharacter described which needs no conditioning prior to the formationof type impressions therein, since its operation is entirely independentof such factors as moisture. content which is so critical a factor inthe type of matrices commonly used today.

Another object of this invention is to provide a foil mat matrix of thecharacter described which is both simple in construction and rela tivelyinexpensive to produce.

Another object is to-furnish a matrix which can be used with, suitableliquid plastic materials- Figure 2 is a perspective view of a greatlyen.

larged section of a matrix of the type shown in Figure 1 showing theform of impression produced therein by striking the surface thereof withthe type of a typewriter;

Figure'S is an enlarged plan view of a portion of a matrix of the'type'disclosed in Figure -1 showing several impressions thereon made by thetype of a typewriter; and

' Figure 4 is a greatly enlarged perspective view of a section of matrixembodying an alternative form of the invention.

Turning now to'Figure l, the greatly enlarged matrix illustrated thereinis formed of a plu-' rality of layers of metallic foil such as thelayers 2, 4, Band 8, each such layer having a plurality of closelyspaced, substantially Vertical deformations l0 formed therein. I Thelayers of metal foil are superposed as shown so as to form a mat There-' having amore or lesscellular structure. sultant mat is," forexample, of much greater depth or thickness'than a similar mat would beif made upof the same number of layers of foil whichdid'not' have theexpanded thickness as described resulting from the presence of aplurality of relatively minute deformations in each sheet r 1 Theplurality of foil layers may be formed into a mat by any suitable means.It has been found that no adhesive agent is required between theindividual foils, and a very satisfactory method is to merely bind thelayers together along the edge by suitable crimping or edge binding ofsome suitable character. Satisfactory mats have been formed also bymerely folding sheets over on each other and relying only on thefrictional contact of the individual layers and the folded edges tomaintain the layers in proper alignment. Mats have been formed with verythin coatings of adhesive between the layers of foil, however, whichhave also been found to be satisfactory, although not representing anecessary construction.

The mat so formed provides a sheet of material which may be inserted inan ordinary typewriter and by strikin the desired keys thereof anycombination of letters may be impressed in the mat. When eachkeylstrikes the laminated sheet or mat, it forms a very clean-cutimpression of the type carried by the type bar and normally does sowithout rupturing the surface of the mat and without deforming the rearsurface thereof. Depressions are thus formed in the mat of the exactshape of the type without rupturing or straining the sheet, and thedisplacement of the material in the various layers incident to theproduction of these depressions is localized in such a way, due to thecellular construction thereof, that the immediately adjacent areas areunaffected, which areas must necessarily be kept intact for receivingthe impressions or characters of other letters.

The unusual and very desirable effect thus achieved is apparently theresult of the preliminary deformation of particularly the upper layersof material, and thus providing an excess of vertically deformablematerial at any particular point so that the depressions made by thetype may be formed readily without undesirable effects, such asrupturing of the mat. This preliminary deformation of the foil may beconveniently referred to as depth expansion thereof, and the term willbe so used throughout this specification.

The section of matrix illustrated in Figure 2 is a greatly enlargedportion of a mat which has been struck with the type bar of a typewritercarrying the period" character, and the formation of a depression I!having that particular form is well illustrated therein. The areas l4immediately surrounding the actual type character also are depressedslightly, as shown, which effect has been found to be more pronounced inthe relatively small characters, such as the period, than in theformation of the larger characters, such as letters and the like. These,however, also have this slight deformation H5 at their periphery (asshown in the plan view, Figure 3), although the impression of thecharacter itself is clean-cut and smooth, and the ultimate result ofthese slight peripheral depressions I 4 and I6 is merely that the typewhich is cast from the matrix will be raised slightly higher than itwould be if the impressions formed consisted only of the actualconfiguration of the type and were therefore not quite so deep. Thisactually is desirable, since it insures the cast type impressions ofbeing clear of possible slight inadverent deformations in the matrix andtherefore in' the plate of cast type. In any event, the printingsurface, or highest portions, of the cast type cor responds to thelowermost portions of the depressiors, which portions are thus formed inthe manner Which makes them very clean-cut and free from undesirabledeformation.

Both before and after the matrix has the type impressions formedtherein, it possesses adequate physical strength to enable it to beeasily handled during the necessary operations in the printing process,such as placing it in the typewriter, passing it therethrough andsubsequently casting the plate of type therefrom.

As shown in Figures 1 and 4, various forms of vertical deformations inthe foil may be utilized to producethe depth expansion of the layers. InFigure 1, for example, the deformations are in the form of very smallcuplike pockets or dimples I0, Whereas the surface of the foil, shown inFigure 4, has been given a more or less reticulated form resulting froma plurality of very fine SCOIiIlg lines 18 being formed therein runninghorizontally and. vertically of the sheet. A mat made up of a pluralityof layers of either of these types of depth expanded foil has a ratherunexpected soft flexibility approaching that of heavy cloth. Obviouslyany manner of vertical deformation is suitable as long as it providesthe excess of deformable material at any one point in the upper surfaceof the matrix.

The foil utilized in forming the matrix may be made of any suitablemetallic material, such as aluminum, tin, lead, and various alloys, suchas lead and tin; lead and antimony; lead, tin and antimony; and lead,antimony, zinc and copper. The gauge of the foil will necessarily varywith each particular material and the relative softness thereof.However, as an example, it has beenfound that when aluminum is utilizedit is not practical to use foil thicker than .02 of an inch. Verysatisfactory results have been obtained utilizing aluminum foil having athickness of approximately .002 of an inch. This thickness refers to theusual gauge of the smooth surface foil, and is not indicative of theincreased depth of the sheet resulting from the embossing describedabove, since in the case of this aluminum foil, for example, it has beenfound possible to give a sheet .002 of an inch thick an effectivethickness of approximately .007 of an inch by proper depth expansion ofthe character described.

This latter expansion was produced by using a Ben Day screen of about 65lines to the inch engraved to a depth of about .005 of an inch. Agreater expansion would undoubtedly be possible if a more deeplyengraved plate were used. To obtain the embossing, the foil was placedon the metallic Ben Day plate, and on top of the foil so placed wasplaced (a) a thin sheet of rubber, (b) a sheet of cork, (c) a sheet offibre, and the whole mass then subjected to a pressure of about 3000pounds per square inch with a suitable pressure roller.

The rubber, cork and fibre layers apparently act under pressure in sucha way as to force the foil into the Ben Day design which results in thefoil itself having such a design formed therein. In mass production ofsuch a foil, undoubtedly the smooth foil could be passed between tworollers, namely, a metal roller engraved with the Ben. Day design andthe other covered with cork and rubber.

The foil which is utilized apparently can be as thin as is felt to bedesirable, although obviously the thinner the foil layer, the morelayers that will be required to make up a suitable mat. It should beunderstood also that this invention is, of course, not restricted to anyparticular number of layers of foil in the laminated mat, the onlyrequirement being that a sufficient number of layers must be employed togive the depth of metallic material required for the form and size oftype which is to be employed to impress the matrix. Obviously, the morelayers that are utilized, the thicker the mat will be,and the deeper thetype impression which can be formed therein. By way of illustration,satisfactory work has been done in making platesfornewspaper printing ona rotary press using a mat having between 9 and 16 layers of aluminumfoil having relatively minute, substantially vertical deformationstherein in the form of a myriad of small, dimple-like depressionsarranged in closely spaced rows, as shown in Figure l.

Of course, when a suitable backing sheet is utilized, as has been foundto be possible, the number of sheets of foil required is correspondinglyreduced. The mat should incorporate, however, at least one surface sheetof metal foil which is reticulated or otherwise deformed, preferablyaccording to a suitable, predetermined pattern, to supply an excess ofdeformable foil material at any particular pointwhich in turn permitsthe foil to yield when struck .by type and to form depressionscorresponding t the shape of the type, without actually rupturing orstrain-' ing the foil to the rupture point. If a'ba'cking material issubstituted for some of the metal foil sheets below the impressedsurface of themat, it must be quite similar to those sheets which itreplaces in its physical characteristics so that, in addition tosupporting the metallic surface sheet or sheets, it will at the sametime permit the proper deformation thereof, and will also be deformableitself within the confines of its own depth.

In other words, the backing material must have characteristics similarto the embossed foil sheets which it is used to replace, at least ineffect. This may be provided by utilizing backing material having aircells or spaces within its internal structure. Cellulose wadding is=atypeof material which conforms to this definition, al-" though ifutilized, such wadding should be impregnated with a wax or similarrigidifying or yielding substance. Other cellulosic substances have beenfound to be suitable, such as cardboard, blotting paper, and the like.No attempt'is being made to define all of the possible structures andmaterials which will produce a backing of the type defined. It should beunderstood, how;- ever, that the invention in its broadest conceptshould include any form of suitable backing which gives the action heredescribed, namely, that of permitting a displacement through bodilymovement or flexibility of the mass constituting the backing layer, intospaces also contained within the confines of the backing layer, so thatthe metallic surface sheet or sheets can be in deformed and thusprotrude into the backing layer without causing that backing layer to bedisplaced beyond the confines of its normal dimensions. Thischaracteristic of the backing layer, in turn, prevents the metallicsheets from being ruptured.

The lack of necessity for further defining the tage, 'the foil matrixprovides an equally outtype of backing material which may be utilizedshould be clear from the fact that the vertical deformation of themetallic foil which is utilized as an upper surface of the matrix isneeded primarily to supply excess of deformable metal, whereas when alaminated mat, made up of a plurality of layers of metal foil alone isemployed, the depth expansion in the underlying metal foil sheets whichconstitute the backing for the mat is utilized primarily for itscellular structure rather than to'supply an excess of deformable metal.With this difference in mind, it can readily-be 'seenthatthe mainpurpose of. the backing sheetor sheets, when not depth expanded metalfoil, is still to provide an intercellular structure,

and-therefore an opportunity for variation as to structure and materialsemployed is present.

The matrix described may have the desired type impressions formedtherein in a typewriter in substantially the same amount of time thatany sheet of typing may normally be prepared. This in effect means thata matrix from which a plate of type may be cast can be formed directly,without first having to assemble a plate of type in'some manner orother, such as through the The fact that the'impressed matrix can beformed readily in a typewriter is a very great advantage, but inaddition to that distinct advanstanding' one in the preparation of amolded plate of type from it, The foil mat matrix canbe used with anumber of very desirable fiowable plastic materials which set up quicklyto form plates of type and which do not require the application ofeither heat or pressure thereto in the molding process;

Obviously a foil matrix of the type described is not suitable for usewith molten type metal. Such a matrix does lend itself to the use of asuitable flowable plastic material which can be poured, while cold,directly onto the foil matrix, however, after the type impressions havebeen formed therein and which preferably willharden quickly to form aplate of type without the use of heat or pressure. One such methodinvolves the use of a gypsum material known as Hardite," which is asubstance widely used for making dental molds and is supplied, forexample,by the Wiggins Company of Bloomfield, New Jersey. This materialmay be mixed with water to form a slurry having a consistency of aboutthat of melted ice cream. The previously impressed matrix is preferablysupported on a casting box having upstanding side walls, which determinethe thickness of the finished plate, and a hinged top which may bebrought into place on the side walls in a manner which extrudes theexcess material. The castingbox is also preferably mounted so that itmay be rapidly vibrated during the casting operation, which vibrationcauses any entrapped air to move out of association with the impressedfoil and up toward the top of the molding box. Intimate contact is thusassured be tween the liquid Hardite and the pressed foil.

The Hardite sets up in a very short period of time, somewhat likeplaster of Paris, and it has been found that in approximately 10 minutesit normally has becomehard enough to permit the foil matrix to bestripped therefrom and a light weight plate of type results. Additionalremoval of moisture from the plate is ordinarily necessary, however, togive the Hardite additional hardness, but care must be taken not tover-dry it, as it will then become brittle. The preferred method ofdrying is that of heating the Hardite in an oven maintained atapproximately 200 F. for a period of approximately ten minutes. Theplate'so formed can then be used as a plate of type'for producingmatrices of the conventional type as explained above.

As also mentioned in the co-pending application referred to above, amore desirable plastic material, in many respects, for use substantiallyin the manner described, is methyl methacrylate. This material isadvantageous in that it requires no heating to cause it to set up into aplate which can be readily utilized directly for printing or which canbe used for the production of conventional matrices. However, only onemethyl methacrylate plate can normally be made from a single matrix ofthe character described, but due to the fact that this type of plate hasvery unusual wearing properties and therefore increased life, it willreplace in use approximately two conventional metal plates. Also,additional methyl methacrylate plates can be made as required throughthe utilization of additional foil mats which can be readily impressedfrom the first methyl methacrylate plate rather than being formed in atypewriter. In this way any number of plates can be produced with verylittle expense and difficulty. These new foil mats can be produced fromthe methyl methacrylate plate with only very slight pressure. This isimportant, since extreme pressure is required to make the conventionaltype of dry mats from the plate of type, with the result that only about15 conventional mats can be made without damaging the type beyond thepoint of further use.

These light weight, cold-set plastic plates cannot be made from theconventional type of matrix discussed above. This limitation isparticularly significant in the light of the fact that it is thepractice today to keep in storage printing patterns made of type metalfor use in making reprints of previously published material, as the needarises. Some of the larger publishing companies, for example, have greatamounts of capital tied up in metallic patterns, both in the relativelycostly patterns themselves and the expensive structures required tosatisfactorily store and support such heavy material. The substitutionof light weight methyl methacrylate plates, for example, for thoseplates of metal would provide a means of producing and storing printingplates at a fraction of the present cost, by the great reduction inspace requirements and weight handling, in addition to the much lowercost of materials.

Although, for purposes of this discussion, we have treated the plasticplates as being formed in only one piece, it should be obvious that alaminated structure could be utilized, since it might be desirable toprovide the plastic with a suitable backing of other material. Becausethe hardened plastic surface of the methyl methacrylate plate is capableof withstanding high pressures, it is possible, for example, to secure asheet of suitable pressure sensitive plastic or thermo-plastic materialto the back thereof. This has the additional advantage of assuring aperfectly smooth back for the finished plate, which is normallyessential for accurate printing or stereotyping. Such a procedurepermits the use of a plastic for the surface of the printing plate whichproduces an excellent printing surface without damage to the matrix,such as the methyl methacrylate, while a material particularly suitedfor use as a backing material may be utilized in combination with theideal printing surface material.

What is claimed is:

1. A flexible, malleable, laminated foil mat for use as a matrix forstereotype plates, which mat has dimensional stability and is adapted tobe inserted in a typewriter to have type impressions formed thereincomprising a plurality of superposed layers of deformable thin metallicfoil, each layer having throughout substantially its entire surface aplurality of relatively minute protuberances of a height and beingspaced from each other a distance comparable to the thickness of saidlayer, said protuberances providing a substantially increased surfacewithin a particular area of foil, the extended surface of said layers offoil adapting said matrix to receive without rupturing a plurality ofrelatively deep impressions when struck with the type on selected typebars of a typewriter.

2. A flexible, malleable matrix for stereotype plates having dimensionalstability and being adapted to be inserted in a typewriter to have typeimpressions formed therein comprising a plurality of layers of thindeformable metallic foil each layer having throughout substantially itsentire surface a plurality of relatively minute protuberances of aheight and being spaced from each other a distance comparable to thethickness of said layer, said protuberances providing a substantiallyincreased surface within a particular area of foil, and a compressible,cellular backing therefor, the extended surface of and the compressiblebacking for said foil adapting it to receive without rupturing aplurality of relatively deep impressions when struck with the type onselected type bars of a typewriter.

3. A flexible, malleable matrix for stereotype plates having dimensionalstability and being adapted to be inserted in a typewriter to have typeimpressions formed therein comprising a plurality of layers of thin,deformable metallic foil each having throughout substantially its entiresurface a plurality of closely spaced, relatively minute, depressionsformed therein of a depth and being spaced from each other a distancecomparable to the thickness of said layer and a compressible, cellularbacking therefor.

4. A flexible, malleable, laminated foil mat for use as a matrix forstereotype plates, which mat has dimensional stability and is adapted tobe inserted in a typewriter to have type impressions formed thereincomprising a plurality of superposed layers of thin, deformable metallicfoil, each layer having throughout substantially its entire surface aplurality of closely spaced, relatively minute, depressions formedtherein of a depth and being spaced from each other a distancecomparable to the thickness of said layer.

5'. A flexible, malleable, laminated foil mat for use as a matrix forstereotype plates, which mat has dimensional stability and is adapted tobe inserted in a typewriter to have type impressions formed thereincomprising a plurality of superposed layers of thin, deformable metallicfoil, each layer having throughout substantially its entire surface aplurality of closely spaced depressions embossed thereon, each saiddepression having an area which is relatively minute with respect tosaid type impressions and being of a depth and being spaced from eachother a distance comparable to the thickness of said layer.

6. A flexible, malleable, laminated mat for use as a matrix forstereotype plates, which mat has dimensional stability and is adapted tobe inserted in a typewriter to have type impressions formed therein,comprising a plurality of sheets of thin, metallic foil havingthroughout substantially its entire surface a plurality of closelyspaced, relatively minute protuberances formed in each sheet of a heightand being spaced from each other a distance comparable to the thicknessof said sheet, and a relatively rigid but compressible backing sheethaving a relatively open structure so that relatively deep impressionsmay be formed in said surface sheet such as those produced by strikingthe surface sheet with the type of a typewriter Without rupturing thesurface sheet and without deforming the exposed surface of said backingsheet.

7. A flexible, malleable, laminated foil mat for use as a matrix forstereotype plates, which mat has dimensional stability and is adapted tobe inserted in a typewriter to have type impressions formed thereincomprising a plurality of superposed layers of deformable thin metallicfoil, each layer having throughout substantially its entire surface aplurality of intersecting line depressions embossed thereon forming inturn a plurality of closely spaced, relatively minute protuberances of aheight and being spaced from each other a distance comparable to thethickness of said layer.

8. A flexible, malleable, laminated foil mat for use as a matrix forstereotype plates, which mat has dimensional stability and is adapted tobe inserted in a typewriter to have type impressions formed thereincomprising a plurality of superposed layers of thin, deformable metallicfoil, each layer having throughout substantially its entire surface atleast two angularly disposed sets of closely spaced parallel linedepressions embossed thereon forming a plurality of closely spaced,relatively minute, protuberances of a height and being spaced from eachother a distance comparable to the thickness of said layer.

9. A flexible, malleable, laminated foil mat for use as a matrix forstereotype plates, which mat ances of a height and being spaced fromeach other a distance comparable to the thickness of said layer. 1 i I10. A flexible, malleable, laminated foil mat for use as a matrix forstereotype plates, which mat has dimensional stability and is adapted tobe inserted in a typewriter to have type impressions formed thereincomprising a plurality of superposed layers of thin, deformable metallicfoil,

each layer havingthroughout substantially its entire surface a pluralityof closely spaced parallel line depressions embossed thereon of a widthand a depth comparable to the thickness of said layer and being spacedfrom each other a distance les than ten times the thickness 01' saidlayer.

FRANK J. RUSSELL, JR;

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,802,379 Higginson Apr. 28, 1931 2,008,181 Kemp July 16, 19352,098,193 Munters Nov.'2, 1937 2,101,836 Benedict e Dec. 14, 19372,129,488 Bomberger Sept. 6, 1938 2,173,815 Slisz et al Sept.19, 19392,406,815 Elfving Sept; 3, 1946 2,486,669

Nassimbene Nov. 1, 1949

1. A FLEXIBLE, MALLEABLE, LAMINATED FOLL MAT FOR USE AS A MATRIX FORSTEREOTYPE PLATES, WHICH MAT HAS DIMENSIONAL STABILITY AND IS ADAPTED TOBE INSERTED IN A TYPEWRITER TO HAVE TYPE IMPRESSIONS FORMED THEREINCOMPRISING A PLURALITY OF SUPERPOSED LAYERS OF DEFORMABLE THIN METALLICFOIL, EACH LAYER HAVING THROUGHOUT SUBSTANTIALLY ITS ENTIRE SURFACE APLURALITY OF RELATIVELY MINUTE PROTUBERANCES OF A HEIGHT AND BEINGSPACED FROM EACH